Phonograph



June'lz, 1923.

H. ROTHKIRCH PHONOGRAPH 2 Sheets-Sheet l Filed April '7, 1921 June 12,1923.

)1,458,596 H. RoTHKlRcH PHONOGRAPH Filed April 7, 1921 2 Sheets-Sheet 2w/r/vfssfs VENo/e. 2g. www By MQW/@kw A UUR/VE VS Patented June 12, 1923FIQEo PHONOGRAIH.

Application filed April 7,

To zZZ 'whom t may concern: y

Be it known that I, HERMAN Ro'ri-IKIRCH, a citizen of the United States,and resident of the borough and county of Queens, city andState of NewYork, have invented cer-A tain new and useful Improvements inPhonographs, of which the following is a specification.

My invention relates to phonographs and has for its object to provide aninstrument of this character which is of maximum efficiency in thereproduction of the records be-v ing played and in which allobjectionable and foi'eign noises are eliminated from 'saidreproduction. Other more specific objects of my invention will appearfrom the description hereinafter andthe features of novelty will bepointed out in the appended claims. Y f n Reference is to be had to theaccompanying drawings which illustrate an enample of my invention`without dening its limits and in which Figure 1 is a plan view of myimproved phonograph; Fig. 2 is a sectional elevation thereof; Fig. 3 isa horizontal -section on the line 3-3 of Fig. 2; Fig. f1 is a frontelevation; Figs. 5 and 6 are detail views of the tone arm; and Fig. 7 isa view illustrating a detail of the invention.

As shown in the drawings, the phonograph comprises a casing 10 ofsuitable conformation and which, as shown, may be constructed tosimulate a grand piano and in any event diverges toward its front oroutlet end and constitutes in itself ay part ofthel sound conduit of thephonograph. lVhen constructed as illustrated in the example shown, thecasing 10 may be mounted upon legs or other supports 11 and may beprovided with a closure whereby the eXi-t end is capable of beingclosed. As shown, the closure maycomprise a cover 12 and a carryingmember 13 shaped to correspond to the customary key-board cover of thepiano, the carrying member being preferablyv constructed to provide,anopening 14 for the escape of the sound when 'the cover 12 vis closed.In the preferred arrangement, the closure is completely removable and isheld in place, for instance, by means kof blocks 15 carried by themember 13 land arranged' to be clamped beneath lugs 16 located upon thecasing 10, by means of resilient locking members 17 also located on saidcasing 10. With the arrangement described and assuming the closure to bein place, the cover12 1921. Serial No. 459,300.

n may occupy either the closed position shown in full lines in Fig. 2,in which lcase the` muffled sound escapes through the opening 14:, orthe open position shown by dotted line in said ligure or said closuremay be completely removed by simply overcoming the resistance of thefastening devices 17 to completelyopen the outlet end of the casing 10,`

in either of which cases the escaping sound is of increased loudness.k

y'The top of the casing 10 consists ofa fixed member 1S ofrelativelylight .construction and a removable cover 19 of relatively heavierconstruction and insulated from the casing 10-and hired member 18, 'forinstance' by means of leather or similarfmaterial 19 as shown in Fig. 2,said cover 19 being detachably secured in. place in any suitable manneras, for instance yby means of screws 20, the heads of which arepreferably in sulated with leather or similar covers 21,-and

lever 27 for controlling the starting andk stopping of the motor islocated in a readily accessible position and a speedchanging device 28of any well known type may also be included in the arrangement. Thebottom 29 of the casing 10 is constructed so as to be ex tremely'responsive to vibration and is made of relatively thin material,preferably wood,

vand at 'its forward edge may be provided with a reinforcingstrip 30;Lin the preferred arrangement, said bottom 29 is curved in wardly bothlongitudinally, as indicated iii Fig. 2, and transversely, as indicatedby dotted lines in Fig. 4. This result is attained by bendng the woodand thereby placing at least some of thefibres thereof under a tensionwhichserves to increase theres-financey of the bottonito a maximumdegree. l tone arm 31, which constitutes a part of the The soundconduit, is preferably of rectangular cross-section and kin itspreferred vembodment 1s constructed entirely of wood 1n a curved form,as shown in Fig. 2, and at its forward end communicates with and carriesthe reproducer 32 which may be of any existing type. In its illustratedform, the upper and lower walls of the sound conduit or,`morespecifically, the tone arm 31 are bent into curved form whereby at leastsome of the fibres of the wood-are placed under tension and theresonance of lthe tone arm as a whole is also increased to a maximumdegree. It will be understood that this method of increasingA theresonance of the bottom 29 and tone arm 3l may be applied with equalsuccess to sound conduits of other and different construction than thatshown in the drawings. The tone arm 3l, in the illustrated example,extends through a suitable opening 33 in the top member 18 and isprovided with a pivot member Bil which is seated in a socket 35 formedin a coupling head 36; the latter is mounted upon a resilient member 37preferably constructed of wood and having its one end secured to abridge or block 38 which in turnvis fastened to the bottom 29 atapproximately its central point, Aas .shown in F ig. 2. Vith thisarrangement the tone arm is resiliently supported upon the bottom of thecasing in a manner to yield vertically `and so as to be movable acrossthe record in a horizontal plane in the .usual way. For the purpose ofabout the coupling member 36 and forms` an opening etOn through whichthe lug 39 may be passed in one position to disconnect the tone arm 31from the -coupling member l3G; the opening 41 is clearly shown in Fig. 3and is so located that it is necessary, in order to permit disconnectionof said tone arm from the coupling member, to bring the tone arm toaposition other than any position assumed by it in the operation of theinstrument. The tone arm 3l communicates by way of its open `end 31awith the interior of the casing ll0 or, in other words, `with the soundconduitV provided thereby, it being understood that if desired, a cap orother device ll, preferably of a flexible material, may be provided onsaid tone arm 31 for closing the opening 33.

All of the parts of the phonograph which, in any way, contribute to thetonal quality of the instrument are constructed of wood and thefastening devices, such as screws, are maintained out of contact withvsaid parts, for instance by passing through oversize holes and by beinginsulated with leather or other suitable material to eliminate allobjectionable and metallic sounds. Because of the resili'ent mounting ofthe tone arm and because of the relatively thin bottom 29 upon which itis supported, the instrument is rendered supersensitive with the resultthat the vibrations set up by the reproducer in co-operation with therecord being played are sympathetically amplified and are communicatedto the listener by way of the open end of the casing l() as an etlicientreproduction of the original represented by the record in question andwith all metallic and other foreign noises entirely 'eliminated fromsaid rep-roduction. The resonance of the instrument and its reproductivequality vare further increased by bending the wood or certain partsthereof of which ythe element or elements constituting the sound conduitare constructed. lVhile itis preferred from Aan ornamental standpoint toconstruct the phonograph, for

instance in the form ofv a grand piano, it will be understoodthat thisis not arbitrarily necessary and that any other divergent form may beused whereby the sound passing through the sound conduit, as exemplifiedby the casing l0, is ampliied,

It will be noted that the motor 22 and the table 25 and all partsco-operating therewith are carried by the top member or cover 19, thelatter being insulated from the ca sing while the screws 22a wherebysaid motor is suspended are insulated from the cover 19; the motor andits correlate/d parts thus in no way interfere with the vibrationshereinbefore referred to and in no way contribute any vibrations oftheir own whereby the tonal quality of the. phonograph might bedetrimentall-y affected.

My improved phonograph is extremely simple in construction and reducesthe number of parts to a minimum, and at the same time, provides aninstrument whereby all of the natural qualities of the original fromwhich the record is made are preserved in the reproduction and allmetallic and other foreign sounds are eliminated therefrom.

Various changes in the specific form shown and described may be madewithin the scope of the claims without departing from the spirit of myinvention.

I claim:

l. In a phonograph, the combination of a casing which itself constitutesthe sound conduit for the passage of sound, said casing having anopening in its upper wall, a

bottom of rrelatively thin wood constituting part of said casing and atone yarm extending from the exterior to the interior of said casingthrough said opening and having its inner end mounted upon said bottomand in communication with the interior of said casing.

2. In a phonograph, the combination of a casing which itself constitutesthe sound conduit for the passage of sound, said casing having anopening in its upper wall, a

5 bottom of relatively thin wood constituting part of said casing andcurved inwardly` both longitudinally and transversely and a tone armextending from the exterior yto the interior of said casing through saidopening and having its inner end mounted upon said bottom and incommunication with the interior of said casing.

3. In a phonograph, the combination of a casing which itself constitutesthe sound 5 conduit for the passage of sound, a tone arm extendingfreely from the eXterior'of saidv casing to the interior thereof andcommu-` 5. A phonograph comprising a casingy which itself constitutes asound conduit, a

bottom of relatively thin material for 'said casing, a bridge locatedupon saidbottom at approximately the Central point thereof,

a member having its one end secured to said bridge' and extendingtherefrom in spaced relation to said bottom to provide a resilientsupport, and a tone arm extendingy freely y vinto said casing andcommunicating therewith, said tone arm being connectedy with andsupported by said member. i 6. A phonograph comprising a casing whichitselfconstitutes a sound conduit, a relatively thin flexible bottom forsaid casing, a resilient member mounted upon said botto-1n and connectedtherewith approximately at its central point', a coupling member carriedby said member, atone arm eX- ytending freely into said casing andmounted' upon said coupling member so as to swing relatively thereto andmeans whereby said tone arm `is connectedy with said coupling memberwithout interference with the swinging movements of said tone arm.L

In testimony whereof I have hereunto set my hand. f

HERMAN RoTHKIRoH.

Witness: y n

JOHN F. KLEIN.

